The tiara was purchasesed upon the recommendation of Lord Plunket, who was Deputy Master of the Household from 1954 to 1975. It was acquired in 1959 before the official announcement by H.M. Queen Elizabeth The Queen Mother on 26th February 1960 of the engagement of H.R.H. The Princess Margaret to Mr Antony Armstrong-Jones. The Princess wore the tiara in its form as a splendid fringe necklace on several occasions before her actual marriage and also as a necklace and brooches on many State and official fonctions throughout the rest of her life. Yet it was on her wedding day, arriving at Westminster Abbey by horse-drawn carriage, that H.R.H. The Princess Margaret first wore this impressive piece as the 'Poltimore Tiara'